Gwen has recently purchased a cottage. she has arranged to have well dug on the property. one in five wells that were dug recently in the vicinity were dry, and 30% of the others were contaminated. find the probability of each of the following: a) gwen’s well will not be dry. (b) gwen’s well will be uncontaminated, given that it is not dry. (c) gwen will have safe drinking water from her well. (d) gwen will not have safe-drinking water from her well.